New mutations do take a very long time and many generations to occure in the genetic code. But our genetic code already holds all the information gathered trough evolution process...even information that are older than mammals.

In case of start of pregnency in zero g or gravity of Mars (0,38 g)... there are many replications from the single cell egg to fetus couple month old...

Can gravity in this case has potentional to "open new variant" of genetic information gathered in our cells? Does diferent gravity has impact on metabolic processes on cellual level?

$\begingroup$It seems like the question here is, "Does a reduction in gravity affect the way that biological macromolecules interact with one another in cells?" Specifically, does low gravity affect gene expression and metabolism? Is that what you're asking?$\endgroup$
– porkchopJan 17 '19 at 2:58

$\begingroup$Yes. That is exactly it. Sorry if it was was not so clear. So is there any study about impact of different gravity?$\endgroup$
– Miroslav ŘešetkaJan 17 '19 at 9:06

$\begingroup$I mean I do not expect that anyone know how exectly the gene expression and metabolism changes on cellual level due to long time in low gravity....I just wanted to understand the potencial of possible changes that can occure. What is the scale of potentional changes we might be able to observe during space clolonization.$\endgroup$
– Miroslav ŘešetkaJan 17 '19 at 9:59

2 Answers
2

No
The question itself does not even make sense, we do not hold onto much unused information, there is nothing to unlock. Unused genes mutate and get co opted for other purposes. We have about a hundred new mutation per generation. Much of so called junk DNA is actually just used for other purposes besides coding for proteins.

Will a colony evolve differently sure, any isolated population evolves along its own lines but it will happen at evolutionary speeds.

It has been known for some time that there are physiological changes associated with spaceflight- bone and muscle mass decrease, and the distribution of fluids in the body changes as well, all in response to the decrease in gravity. This is why astronauts ride exercise bikes when they are in space.

Perhaps the most accessible (and trustworthy) resources I have been able to find about the effects of low gravity on the molecular behavior of cells is from the NASA Twins Study, where one twin of an identical twin pair was sent into space for one year, while his brother remained on Earth. Before and after the year in space, the brothers were sampled and tested in all kinds of ways and interesting changes in gene expression and metabolism were found. For example, many genes changed expression levels in the brother who went to space, but they quickly returned to baseline after return to earth. However, a small number of genes remain at changed levels of expression, suggesting that long-term exposure to low gravity does change patterns of gene expression. It is important to note that these changes are not at the genome level; rather, they are attributed to changes in epigenetic regulation of the genome. You can see a summary of these results here.

My knowledge of evolutionary biology is too thin to comment fully on the part of your question that asks about unused genetic information from earlier stages of evolution, but I would expect that if gene expression and cell behavior changes in low gravity, that several generations of humans living entirely in zero or reduced gravity would be trending toward genetic difference from Earth-bound humans. You wouldn't necessarily see changes in an individual, but over time they could accumulate and cause different regions of the genome to be expressed in ways that humans on Earth do not experience.